U.S. patent number 4,167,556 [Application Number 05/802,379] was granted by the patent office on 1979-09-11 for determination of transcobalamins.
This patent grant is currently assigned to Yissum Research Development Company of the Hebrew University of Jerusalem. Invention is credited to Nathan Grossowicz, Bracha Rachmilewitz, Jacob Selhub.
United States Patent |
4,167,556 |
Selhub , et al. |
September 11, 1979 |
Determination of transcobalamins
Abstract
A process for the quantitative determination of the
transcobalamins TC-I, TC-II, and TC-III in serum. The process
comprises incubating the serum with radiolabeled vitamin B-12,
passing the resulting mixture through adsorption means, such as a
charged cellulose filter or equivalent mini-column, for TC-II at a
pH of about 8.5, adsorbing the remaining TC-I and TC-II components
on a DEAE-cellulose type adsorbent, selectively desorbing the
TC-III component with monopotassium phosphate solution of about
0.05 M and pH of about 4.6, and determining the radioactivity of
each of the three transcobalamin fractions to indicate the
individual and total unsaturated vitamin B-12 binding capacity of
the three transcobalamins in the serum sample tested.
Inventors: |
Selhub; Jacob (Chicago, IL),
Rachmilewitz; Bracha (Jerusalem, IL), Grossowicz;
Nathan (Jerusalem, IL) |
Assignee: |
Yissum Research Development Company
of the Hebrew University of Jerusalem (Jerusalem,
IL)
|
Family
ID: |
25183541 |
Appl.
No.: |
05/802,379 |
Filed: |
June 2, 1977 |
Current U.S.
Class: |
436/505; 206/569;
436/808; 436/541 |
Current CPC
Class: |
G01N
33/82 (20130101); Y10S 436/808 (20130101) |
Current International
Class: |
G01N
33/82 (20060101); G01N 033/16 (); B65D
069/00 () |
Field of
Search: |
;424/1,1.5,12 ;23/23B
;206/569 |
Other References
selhub et al., Febs Letters, vol. 44, No. 1, Aug., 1974, pp. 71-74.
.
Burger et al., J. of Biol. Chem., vol. 250, No. 19, Oct. 10, 1975,
pp. 777706. .
Selhub et al., Proc. Soc. Ex. Bio. Med., 152, No. 2, 1976, pp.
204-209. .
Selhub et al., Chemical Abstracts, vol. 81, No. 23, Dec. 9, 1974,
pp. 205-206, Abstract No. 148007a. .
Bruno et al., New Techniques in Tumor Location and Radio
Immunoassay, Ed. Croll et al., John Wiley and Sons, New York, 1974,
pp. 9-15. .
Jacob et al., Journal of Laboratory and Clinical Medicine, vol. 83,
No. 3, Mar., 1975, pp. 505-512. .
Kumar et al., Proc. Soc. Ex. Bio. Med., 147, 1974, pp. 377-381.
.
Morelli et al., J. Lab. Clin. Med., vol. 89, No. 3, Mar.,
1977..
|
Primary Examiner: Padgett; Benjamin R.
Assistant Examiner: Nucker; Christine M.
Attorney, Agent or Firm: Klawitter; Andrew L.
Claims
What is claimed is:
1. A process for the quantitative determination of each of the
three transcobalamins TC-I, TC-II, and TC-III in serum, which
comprises incubating a predetermined quantity of serum with a
solution of .sup.57 Co Vitamin B-12, passing the resulting solution
through adsorption means adapted to selectively adsorb TC-II on a
charged cellulose filter or equivalent mini-column at a pH of about
8.5; adsorbing the TC-I and TC-III constituents on a cellulose
filter of the DEAE-cellulose type or an equivalent mini-column;
selectively desorbing the TC-III by means of a monopotassium
phosphate solution of about 0.05 M and at a pH of about 4.6, and
determining the radioactivity of each of the three transcobalamin
fractions thus obtained, indicating the individual and total
unsaturated B-12 binding capacity (UBBC) of the three
transcobalamins.
2. A process according to claim 1, wherein the incubation is
effected with 0.1 M sodium borate buffer of pH of about 8.5.
3. A process according to claim 1, wherein the solution of serum
and .sup.57 Co Vitamin B-12 is applied to the filters or equivalent
mini-columns by application of reduced pressure.
4. A process according to claim 1, wherein .sup.57 Co Vitamin B-12
not bound to transcobalamins is removed from the filters or
equivalent mini-columns by means of borate buffer.
5. A process according to claim 1, wherein the TC-II is adsorbed on
a cellulose nitrate filter or mini-column.
6. A process according to claim 5, wherein the TC-I and TC-III are
adsorbed on a DEAE-cellulose filter or mini-column.
7. A process according to claim 1 wherein the TC-I and TC-III are
adsorbed on a DEAE-cellulose filter or mini-column.
8. A kit for the quantitative determination of TC-I, TC-II, and
TC-III, comprising, in combination, a container of .sup.57 Co
Vitamin B-12 solution, adsorption means for the separation of TC-II
from combined TC-I and TC-III, and a container of monopotassium
phosphate solution of about 0.05 M and pH of about 4.6.
9. A kit according to claim 8, wherein the adsorption means
comprises a combination of a cellulose nitrate filter to
quantitatively adsorb TC-II and DEAE-cellulose to quantitatively
adsorb both TC-I and TC-III.
10. A kit according to claim 8, which additionally comprises a
container of borate solution.
11. A kit according to claim 10, wherein the borate solution is
about 0.1 M and at pH 8.5.
12. A kit according to claim 8, wherein the .sup.57 Co Vitamin B-12
is of an activity of from 135-200 .mu.Ci/.mu.g.
13. A kit according to claim 9, wherein said DEAE-cellulose is in
the form of a filter.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The human serum contains at least three known binders of Vitamin
B-12, namely the three transcobalamins designated as TC-I, TC-II,
and TC-III. TC-I and TC-III are derived from granulocytes and both
are alpha-globulins with a similar molecular weight, of about
120,000. They have a different electrical charge and hence differ
in their electrophoretic mobility. TC-II is a beta-globulin of
molecular weight of about 38,000 and it is derived mainly from the
liver. The physiological functions of the three transcobalamins are
not fully understood, but it is known that endogenous Vitamin B-12
is bound mainly to TC-I (about 85%), and TC-II binds about 15% of
endogenous B-12 while TC-III seems to bind Vitamin B-12 only in
vitro. Since TC-II binds small quantities of endogenous B-12 while
it takes up the main part of Vitamin B-12 added to the serum in
vitro, most of the unsaturated B-12 binding sites are located on
TC-II (unsaturated B-12 binding capacity, UBBC). Vitamin B-12 is
bound in the serum to the transcobalamins in a 1:1 molar ratio.
It is well known that certain pathological conditions are
associated with significant specific changes in the level of the
three transcobalamins in serum and that the determination of the
Vitamin B-12 binding capacity of each of the three transcobalamins
is an important tool in medical diagnosis. Amongst others, the
quantitative determination of the B-12 binding capacity of the
three transcobalamins is of value in the effective screening of
certain malignant diseases and also in the monitoring of the
treatment of these diseases. Amongst others, the determination of
three transcobalamins is of value in:
A. diagnosis, evaluation of treatment and monitoring of the course
of myeloproliferative diseases [CML (chronic myelocytic leukemia),
APL (acute promyeolocytic leukemia), polycythemia vera.]
B. differentiation of leukemoid reactions and conditions manifested
by non-leukemic leukocytosis.
C. recognition of rapid malignant cell proliferation in lymphoma,
sarcoma, Hodgkins Disease, acute leukemia, etc.
D. evaluation of therapy and monitoring the course of malignant
diseases (remission and relapse) such as sarcomas, acute leukemias,
Hodgkins Disease, lymphomas etc.
E. diagnosis and recognition of hepato-cellular damage.
The quantitative determination of B-12 binding capacity of the
three transcobalamins may also be of value in the recognition,
differentiation and monitoring of various other disorders.
2. Description of the Prior Art
The three transcobalamins present in human serum are difficult to
separate and their quantitative determination is both complicated
and time-consuming. The main problem is the similarity of
electrophoretic properties of TC-II and TC-III and their similar
behaviour on DEAE-cellulose separation.
The present determinations require at least two steps, namely:
a. DEAE-cellulose chromatography to separate TC-I from TC-II and
TC-III and a Sephadex G-200 column to further separate TC-II from
TC-III;
b. Adsorption of TC-II on charcoal and subsequent separation of
TC-I and TC-III by a DEAE-cellulose chromatography;
c. Selective removal of TC-II from serum by Quso G-32 (a microfine
precipitated silica) and subsequent separation of TC-I from TC-III
on DEAE-cellulose;
d. Separation of TC-II on a G-200 column and subsequent separation
of TC-I from TC-III by a DEAE-cellulose column.
e. Selective removal of TC-II by precipitation with ammonium
sulfate and further separation of TC-I and TC-III from each other
by DEAE-cellulose chromatography.
The above mentioned two-step procedures are rather laborious and
require from two to three days to complete. Thus these are actually
tools of a research laboratory and indeed the known procedures have
not gained widespread acceptance as routine laboratory method in
clinical laboratories.
SUMMARY OF THE INVENTION
The present invention relates to a simple and rapid process for the
fractionation of the three transcobalimins from each other and for
their quantitative determination. It further relates to means for
carrying out this fractionation and determination. The invention
further comprises means in kit form for the above purposes.
The process of fractionation comprises passing the mixture of the
three transcobalamins through a sequence of charged cellulose
filter media, such as cellulose nitrate filters or equivalent
mini-columns, so as to separate TC-II from the other two
transcobalamins; adsorbing the two other transcobalamins TC-I and
TC-III on another medium such as a DEAE-cellulose filter, or
mini-column, and selectively desorbing TC-III from the latter by
means of a monopotassium phosphate solution of about 0.05 M at a pH
of about 4.6. The entire procedure whether using filters or
mini-columns is carried out in a rapid and continuous sequence of
steps which can be completed within about one hour and a plurality
of samples can be tested simultaneously.
Before passing the reaction mixture through the filters or
equivalent adsorption media, the reaction mixture is incubated with
an excess of .sup.57 Co B-12 of high specific activity, in a sodium
borate buffer of about 0.1 M and at a pH of about 8.5. The
radioactivity of the individual three transcobalamin fractions is
determined and this gives a quantitative measure of the Vitamin
B-12 binding capacity of each of the three transcobalamins. The
adsorptions and desorptions are both specific and quantitative and
thus provide a test of high accuracy and entirely adequate for
clinical purposes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is described in the following way of example only in
an illustrative manner, and it is clear that various modifications
and changes can be resorted to in the details of the means used for
the separation procedure.
I. MATERIALS
1. cellulose nitrate filter discs, 25 mm in diameter (Schleicher
and Schull, Dassel, Germany).
2. DEAE-Cellulose (DE-81) filter discs, 25 mm in diameter (The
Whatman Biochemicals Ltd., Maidstone, Kent, England).
3. Millipore type filter holder apparatus for 25 mm discs (The
Tamar Co., Jerusalem, Israel).
4. .sup.57 Co B-12, high specific activity (135-200 uCi/ug, the
Radiochemical Centre, Amersham, Bucks, England). Batches of 10 uCi
were diluted with water to a final concentration of 10,000 ph
B-12/ml and stored in the refrigerator until ready for use.
5. Borate buffer, 0.1 M Sodium Borate adjusted to pH 8.5 with 10 M
NaOH, prepared in glass distilled water and filtered through
cellulose-nitrate filter to remove particles that may interfere
with the assay.
6. Phosphate solution, 0.05 M monopotassium phosphate (pH 4.6)
prepared in glass distilled water, and filtered through
cellulose-nitrate filter as described above. The concentration of
the phosphate is quite critical. No satisfactory separation can be
obtained at lower or at higher concentrations.
II PROCEDURE
(a) determination of UBBC. The filter discs were arranged in a
stack with one cellulose-nitrate disc which was previously immersed
in distilled water, on top of three DE-81 discs. The stack was
placed in the millipore filter holder and washed with glass
distilled water before use. Duplicate samples of the serum (0.01 ml
each) were incubated for 30 min at 37.degree. (with excess of
.sup.57 Co B-12 (100 pg/0.01 ml) and 0.2 ml 0.1 M Sodium Borate
buffer (pH 8.5). After incubation, the mixture was diluted to 10-12
ml with the borate buffer and passed by applying vacuum through the
filter stack. The excess unbound .sup.57 Co B-12 was removed by
washing the filter twice, with 10 ml of the same borate buffer. The
unsaturated B-12 binding capacity (UBBC, expressed in pg of .sup.57
Co B-12 bound per ml of serum, was calculated from the
radioactivity retained by the stack.
(B) Determination of TC-I, II and III binding capacity. The
duplicate samples of serum treated as described for the
determination of UBBC and passed through the filter stack by
applying vacuum. The excess unbound .sup.57 Co B-12 was removed as
described above. Under these conditions TC-II is selectively and
quantitatively adsorbed onto the cellulose-nitrate filter, while
both TC-I and TC-III are adsorbed onto the DE-81 filters. After the
filter stack was washed to remove the excess of .sup.57 Co B-12,
the cellulose-nitrate filter was removed and counted (the first
count). This count represents the unsaturated binding capacity of
TC-II. The DE-81 filter stack was washed with 5 ml borate buffer
and counted (the second count). This count represents the
unsaturated binding capacity of TC-I and TC-III remaining on the
DE-81 filter discs. Transcobalamins I and III were separated by
washing the DE-81 filter stack with 15 ml of 0.05 M monopotassium
phosphate solution (pH 4.6). The stack was again counted (the third
count). This count represents the unsaturated binding capacity of
TC-I adsorbed on the stack after TC-III was removed by the
monopotassium phosphate solution. The unsaturated binding capacity
of TC-III is given by the difference between the second and third
counts.
The results obtained by the above procedure were checked with a
number of the established laboratory procedures known in the art
and a good agreement was obtained. The entire procedure according
to the present invention can be carried out in about one hour and
many samples can be tested simultaneously. Thus this novel method
provides an important novel clinical test which is of great
diagnostic value and which permits one to obtain results in an
easy, speedy and efficient manner.
It ought to be stressed that various attempts have been made to
separate transcobalamins by DEAE cellulose-chromatography. Various
authors have reported experiments at pH 5.8 with 0.1 M sodium
phosphate; at pH 6.35 with 0.06 M phosphate buffer; at pH 6.2 with
0.075 M phosphate buffer; at pH 6.3 with gradient of phosphate
buffer 0.06 M and 1 M NaCl; a gradient of 0.01 M phosphate buffer
(pH 8.0) and 0.3 M (pH 4.5). None of the above separation
procedures was useful for an acceptable quantitative separation of
the two transcobalamins I and III. The results obtained with sodium
phosphate buffers, with monosodium phosphate and with potassium
phosphate buffers were inconsistent and did not give the required
separations. The concentration of 0.05 M monopotassium phosphate is
quite critical. It may vary from about 0.045 to about 0.55, but at
lower or higher concentrations inferior separations of TC-III from
TC-I are obtained. The high pH of the borate buffer is a requisite
for the selective adsorption of the TC-II on the cellulose nitrate
filter.
Instead of the DEAE-cellulose filters there may be used
DEAE-Sephadex mini-column. The filter media used according to the
above description can of course be used in column form.
The present invention also relates to test means in kit form,
comprising the necessary selective separation means, such as
filter-column or stack, chemicals for the required solutions and
.sup.57 Co Vitamin B-12 solution.
Results obtained indicate that various pathological changes can be
readily differentiated by means of the results obtained by the
above method of determination of TC-I, TC-II, and TC-III.
Extensive experiments were carried out with patients having various
types of disease. The procedure used was as set out above. The
results of the determinations is given in the following. The
following summary of the results is grouped as follows:
Group 1: Deals with normals.
Group 2: Deals with chronic myeloid leukemia (CML) and
promyelocytic leukemia (APL).
Group 3: Deals with Polyceythemia vera (PV) and leukocytosis.
Group 4: Deals with acute leukemia, Hodgkins disease and
lymphoma.
Group 5: Deals with hepatocellular damage.
(a) Group 1: Normals
Table - A ______________________________________ Patient B.sub.12
UBBC TCI TCII TCIII No Identificaton pg/ml pg/ml pg/ml pg/ml pg/ml
______________________________________ 1 E.G 700 1884 301 1260 283
2 Y. 570 1764 317 1112 335 3 Y.A 650 2230 356 1696 178 4 A.Z 870
1605 224 1012 369 5 R.M 950 2058 205 1462 391 6 R.Z 550 1925 212
1501 212 7 S.B 800 1720 190 1204 326 8 A.A 500 1360 136 984 240 9
Z.Y 900 1760 229 1355 176 10 O.Y 540 1560 203 843 514 11 H.D 700
1400 196 868 336 12 P.M 750 1500 120 1185 195 13 A.H 700 1484 268
905 311 14 S.A 660 1545 171 1019 355 15 B.A 700 1760 246 1144 370
16 R.A.H 700 1500 165 945 611 17 P.G 800 1588 159 1032 397
______________________________________ From Table A, one can define
the ranges of Vitamin B.sub.12, UBBC and transcobalamins in normal
cases to be as follows: B.sub.12 500-950 pg/ml UBBC 1300-2250 pg/ml
TCI 100-350 pg/ml TCII 800-1700 pg/ml TCIII 175-600 pg/ml
______________________________________
(b) Group 2: CML and APL
Table - B ______________________________________ No Patient
B.sub.12 TCI Indenti- pg/ UBBC pg/ TCII TCIII No fication ml pg/ml
ml pg/ml pg/ml Remarks ______________________________________ 1 R.M
1500 6098 3780 1255 1063 2 A.R 3000 6823 4571 1500 752 3 S.A 2300
6352 3898 1674 780 4 C.P 4000 3623 2174 1196 253 5 Z.S 1300 3085
740 1666 679 in remission 6 A.Y 800 2235 290 1230 715 in remission
7 P.H 1000 2117 509 1025 583 in remission 8 A.I 1600 3970 1192 1627
1151 9 Y.M 1140 3394 1086 1459 849 10 C.Z 4000 2945 1537 1030 878
11 Z.B 1400 2747 1100 1330 317 12 B.A 2750 6461 3941 1163 1358 13
D.T 3000 6740 3628 1550 1562 14 R.A 3200 3660 1756 1574 330
______________________________________
In CML and APL cases there is elevation in UBBC, due to increase in
TCI binding capacity, resulting in high serum B.sub.12 levels.
The increase in TCIII binding capacity is an expression of the
chronicity of the disease, because of the more mature cells present
in the population which produce mainly TCIII. The TCI binding
capacity decreases during chemotherapy and this serves as a
reliable criterion in the evaluation of the effect of the therapy.
Patients in remission, show normal to slightly elevated ranges of
TCI (patients Nos. 5-7). Thus, the test for TCI contributes to
monitoring the course of chronic myeloid leukemia (remission,
relapse and acute crisis) and the response to chemotherapy.
(c) Group 3: PV and leukocytosis cases
Table C
__________________________________________________________________________
Polycythemia vera (PV) and leukocytosis Patient Identi- B.sub.12
UBBC TCI TCII TCIII No fication pg/ml pg/ml pg/ml pg/ml pg/ml
Remarks
__________________________________________________________________________
1 M.P 400 1933 270 870 793 2 M.S 1250 3147 440 1320 1387 3 V.H 700
3352 370 696 2013 500 2941 299 964 1678 following chemotherapy 4
P.Y 900 3352 335 1173 1844 5 G.M 870 2529 227 1466 836 6 A.C 400
2076 228 1079 769 7 Y.Y 650 2176 148 961 997 8 S.M 550 3384 376
1522 1486 9 B.A 750 6461 356 1609 4496 10 M.P 900 2424 387 1284 753
11 B.A 750 2852 370 1369 1113 12 K.P 400 2360 295 979 1086 950 1529
229 902 339 following chemotherapy 13 A.F 700 2289 183 1533 572 14
C.I 200 1970 177 1319 474 15 I.H 370 2294 137 1468 689 16 A.A 700
2117 296 1587 234 17 H.P 800 2000 280 1040 680 18 C.M 1000 2424 387
1405 632 19 C.Z 810 1888 170 1379 339 20 A.I 400 2613 236 1672 705
21 M.G 900 1558 202 898 460
__________________________________________________________________________
In PV and leukocytosis there is elevation in UBBC due to increase
in TCII binding capacity. No changes were noticed in B.sub.12, TCI
or TCII.
In active PV (PV in relapse) associated with increased leukocyte
concentration there is an increase in TCIII serum concentration
(patients Nos. 2,3,4,8,9, 11 and 12). In the non-active PV state
with normal leukocyte concentration, TCIII is normal to slightly
elevated (patients Nos. 1, 13-21). The TCIII binding capacity
decreases during chemotherapy (patients Nos. 3 and 12). Thus, the
test for TCIII contributes to monitoring the course of active
(relapse) PV stages, the response to chemotherapy treatments, and
monitoring the non-active PV stages as well. More important, serum
TCIII binding capacity determination helps in differentiation of
leukemoid reactions and conditions manifested by nonleukemic
leukocytosis.
(d) Group 4: Acute leukemia, Hodgkins disease and lymphoma
cases
Table - D
__________________________________________________________________________
ACute leukemia cases Patient Identi- B.sub.12 UBBC TCI TCII TCIII
No fication pg/ml pg/ml pg/ml pg/ml pg/ml Remarks
__________________________________________________________________________
1 I.A 1000 3647 291 2918 438 2 P.M 730 3763 452 2747 564 3 P.N 900
7568 203 6760 605 900 4018 201 3335 482 Following chemotherapy 4
K.H 750 6000 400 5180 420 750 3037 273 2581 183 Following
chemotherapy 450 2545 127 2188 230 Following chemotherapy 5 M.S 270
2935 376 2431 410 370 1900 171 1349 380 Following chemotherapy 6
Z.H 850 3364 471 2422 471 700 2360 306 1652 402 Following
chemotherapy 7 M.B 900 3030 121 2545 364 300 2000 140 1540 320
Following chemotherapy 450 1900 285 1240 375 Following chemotherapy
500 1360 136 984 240 Following chemotherapy 8 B.A 475 2650 291 1829
530 600 2063 228 1583 247 Following chemotherapy 9 H.M 1000 2300
254 1771 276 500 1700 173 986 571 Following chemotherapy 10 Z.I 580
2739 109 2492 137 670 1834 129 1467 238 Following chemotherapy 700
2000 258 1442 300 Following chemotherapy 900 1760 229 1355 176
Following chemotherapy 11 H.H 200 2360 277 1959 123 870 1930 368
1258 674 Following chemotherapy 12 N.A.A 1200 2000 180 1460 360
Protracted course 13 A.H.N 650 2100 280 1400 420 Protracted course
14 Z.I 600 1760 119 1330 311 Protracted course 15 G.M 1070 1868 280
1309 280 Protracted course
__________________________________________________________________________
(e) Group 5: Hodgkins disease and lymphoma cases
Table - E
__________________________________________________________________________
Patient Identi- B.sub.12 UBBC TCI TCII TCIII No fication pg/ml
pg/ml pg/ml pg/ml pg/ml Remarks
__________________________________________________________________________
1 B.S 950 5300 380 4500 420 500 1475 163 1012 300 Following
chemotherapy 2 Z.A 720 4411 486 3514 411 3 I.P 700 2615 235 2119
261 4 A.A 900 3600 180 3096 324 5 V.V 500 4176 126 3499 551 6 V.A
1000 5100 204 4384 512 7 L.H 850 4650 372 3787 491 8 A.A 450 3500
175 2905 420 9 K.I 700 4900 434 3800 666 10 S.V -- 4500 180 4005
315 11 I.S -- 2910 175 2270 465 12 S.B -- 1500 150 1020 330
Protracted course 13 S.Z -- 2100 147 1680 273 Protracted course
__________________________________________________________________________
Tables D and E relating to acute leukemias, Hodgkins disease and
lymphomas in which there is increase in UBBC due to elevation in
TCII binding capacity. No changes were noticed in B.sub.12, TCI or
TCIII. The increase in TCII is in direct proportion to the
acuteness of the disease. Increase in serum TCII binding capacity
without a change in Vitamin B.sub.12 level may indicate an acute
proliferation of malignant cells of any kind (such as acute
leukemia, Hodgkins disease, lymphomas, etc). This finding may be
useful in the recognition of rapid cell proliferation in malignant
lymphoma and acute nondifferentiated leukemias. The TCII binding
capacity decreases during chemotherapy and thus serves as a
reliable criterion in the evaluation of the effect of the therapy.
Patients during the protracted or remission course show normal
ranges of TCII. However, during the proliferation of the malignant
cells (the relapse stage) increase in TCII binding capacity is
noticed. Thus, the test for TCII contributes to the monitoring of
the relapse course of acute leukemias, Hodgkins disease, lymphomas,
etc., the response to chemotherapy treatments and monitoring the
protracted course or remission as well.
(f) Group 5: Hepatocellular damage
It is well established that increase in serum Vitamin B.sub.12
bound mainly to TCII is characteristic to hepatocellular damage.
The B.sub.12 released from the damaged liver cells saturates TCII
and part of the TCI. As a result, serum binding capacity (UBBC) is
very low while endogenous B.sub.12 bound to TCII is increased.
Since the filter-stack technique determines the UBBC of the
binders, in hepatic diseases the TCII will be very low. This
phenomena is already well recognized and accepted as a valuable
diagnostic aid.
SUMMARY
Determination of serum transcobalamins binding capacity is useful
in diagnosis of the following diseases:
__________________________________________________________________________
UBBC Vitamin of whole Binding Capacity Disease B.sub.12 serum TCI
TCII TCIII
__________________________________________________________________________
CML and APL elevation elevation elevation normal elevation.sup.(1)
PV and leukocytosis normal elevation normal normal elevation AML,
Hodgkins disease normal elevation normal elevation normal lymphoma
Hepatocellular elevation decrease normal decrease normal damage
__________________________________________________________________________
.sup.(1) in chronic cases
Serum transcobalamins binding capacity determination is also useful
in monitoring the relapse courses of these diseases, the response
to chemotherapy treatments and monitoring the protracted or
remission courses as well.
In summary, the three transcobalamins undergo specific quantitative
changes during certain clinical pathological conditions. The
research done on this subject during the last few years has proved
beyond any doubt the clinical significance of the changes in the
transcobalamins binding capacity. The determination of the various
serum transcobalamins binding capacity is today an important tool
in diagnosis as well as in evaluation of the effects of
treatment.
* * * * *